CDC has gone viral (no pun intended). Rear Admiral Ali Khan posted on the Public Health Matters blog about a Zombie Apocalypse and how it relates emergency preparedness. As of this posting the site was down presumably because the post has received coverage from hundreds of news outlets such as Washington Post, Los Angeles Times, USA Today, CNN, and many others. Even the Wikipedia article for "Zombie Apocalypse" was updated citing the reference and it is a trending topic on Twitter.
In my opinion this is an excellent example of the federal government leveraging relevant memes and social media to effectively communicate to the American people. Lets face it, if you are prepared for a Zombie Apocalypse you should be good for anything else.
** UPDATE – 5/19/2011 @ 6:24 PM EST **
Looks like the zombie apocalypse wave has hit Google: